-The genes Isocitrate deshidrogenase 1 (IDH1) and IDH2 are commonly mutated in low grade glioma and GBM. They co-ocur with 1p/19q codeletions and mutations of p53 and ATXR. -In an study, clonal evaluation is detectable in 24% of the patients. Follow up of karyotype is important in patients with lower risk and intermediate risk MDS to evaluate risk of leukemic transformation. -Neuroendocrine tumors are commonly associated with fibrosis, local and distant. Fibrotic complications like carcinoid heart disease and mesenteric desmoplasia lead to morbi-mortality. Role may be played by serotonin, other peptides and growth factors. -Sarcomatoid RCC show higher PD-L1 and PD-1 expression and more density of CD8 positive cell density than grade 4 clear cell RCC, indicating notable immunosuppressive environment in sRCC. PD-1/PD-L1 blockade therapy is a potential therapeutic approach in sarcomatoid RCC. -HPV 16E antibody levels are higher in patients with p16 positive oropharyngeal Ca. This antibody has sensitivity and specificity in the risk stratifications and may be used in future screening trials.

-Ros 1 is a receptor of tyrosine kinase regulate cellular proliferation and may present rearrangements in 1-2% of NSCLC, but also in other AdenoCa, GBM and IMT. This gene can be detected by FISH, PCR and sequencing. The tlyrosine kinase inhibitor Crizotinib is an effective inhibitor of ROS1. -In Atypical breast cytologies/FNA, features associated with malignancy are older age, lower % of epithelial cell clusters, high % of individual cells, cribiform architecture in clusters, intracellular mucin, increase cell clusters without myopithelial cells, diminished fibromyxoid stromal fragments and reduced bipolar nuclei and necrosis. -Gliosarcomas are considered negative for BRAF V600E . This issue of JCP published two cases of gliosarcoma harbouring the mutation, one case de novo, the other arising from ganglioglioma.

- The expression of follicular helper T cells (TFH), EBV, RHOA (G17V) and IDH2 is important in the diagnosis of AITCL. -Homozigous XX complete Hydatidiform Mole (ectopic androgenetic) is associated with risk of significant gestational trophoblastic disease, not intraplacental. Biparental chorioca detected in postpartum uterine sample is consistent with undetected intraplacental Choriocarcinoma. -Cholangitis lenta is a subacute nonsuppurative cholangitis associated with ductular cholangiolar cholestasis (inspissated bile in dilated ductules). Many are liver transplant recipients with signs of sepsis, positive cultures and high mortality. -SFT of head and neck are uncommon. No sex predilection. Average age 52 y/o. Most common sinonnasal tract and orbit, also oral cavity or salivary gland. Hemangiopericitomatous and angiofibroma patterns are common. Lipomatous differentiation is possible as nuclear atypia, epithelioid morphology and coagulative necrosis. Infiltrative pattern or osseous invasion is possible.40% recur.Only rare cases metastasize to sites as lung or bone. -Arteriolized capillaries, subendothelial fibrin deposits and perivascular hyalinization are features of myointimal hyperplasia of mesenteric veins in biopsy samples of cases associated to ischemic colitis. -Renal transplant recipients with immunosuppressive regimen may develop a form of IBD with chronic active colitis, crypt epithelial apoptosis, architectural distortion and basal lymphoplasmocytosis -PAX 8 has been regarded as specific for serous carcinoma. But PAX 8 is really expressed in both benign and malignant mesothelium. BAP1 loss may be confirmatoryin cases of mesothelioma. -Pleuroparenchymal fibroelastosis (PPFE) is associated with intraalveolar fibroelastosis, visceral pleural fibrosis, vascular fibrointimal thickening and granulomas/chronic inflammation. It is a type of idiopatic interstitial pneumonia with features similar to hypersensitivity pneumonia. -HPVrelated multiphenotypic sinonasal shows solid nests of basaloid cells with high mitosis. Cribiform areas may appear similar to adenoid cystic Ca. Squamous differentiation is possible, as well as sarcomatoid or chondroid differentiation or prominent epithelial myoepithelial Ca like growth. All are p16 positive, many HPV 33+. It behaves in a relatively indolent manner. -HPV is not frequently detected in squamous Cell Ca arising from nontonsillar regions of the oropharynx.

-HPV 16 is the most common high risk HPV type identified in oropharyngeal and cervical neoplasia, commonly located in dysplasia at the tongue and floor of the mouth with parakeratosis and hyperkeratosis. -Cases of double or triple extra copy lymphoma were defined by the presence of increased MYC copies and increased BCL2 and/or BCL6 copies or rearrangemenet. -Complete H3K27me3 loss is a moderately sensitive and relatively specific marker for the dx of MPNST when differential diagnosis includes synovial sarcoma and fibrosarcomatous DFSP. -Pancreatic intraductal tubulopapillary neoplasm is genetically distinct from intraductal papillary mucinous neoplasm and ductal adenoca.